Appraisal of surgical treatment of 47 cases of patellofemoral instability

INTRODUCTION: Patellofemoral instability is a common knee disease. Its etiology is complex and variable, with many components making different contributions in each individual, resulting in several distinct clinical presentations. Our goal was to analyze the results of surgical treatment in our hospital over a period of 10 years. PATIENTS AND METHODS: We analyzed 55 knees of 47 patients who underwent surgery for patellofemoral instability and were classified into 2 main groups: proximal realignment and combined proximal and distal realignment. Three other groups were analyzed according to the duration of preoperative symptoms: less than 1 year (group I); 1 to 10 years (group II); and more than 10 years (group III). RESULTS: There were 62% good results overall, with 78% good results in groups I and II. Group III had 81% bad results, showing that a late diagnosis of advanced disease results in a poor prognosis. In addition to late diagnosis, bad results were usually associated with incorrect diagnosis or choice of surgical technique. There was no significant difference between isolated proximal realignment and combined proximal and distal realignment in groups I or II, but in group III, the combined technique yielded better results. DISCUSSION: Our results indicate that patellofemoral instability should be addressed in its early stages. Patients with long-lasting symptoms or more severe disease seem to achieve better results with combined techniques. CONCLUSION: Proximal and distal realignments produce better results than isolated proximal realignment in patients with joint degeneration or with greater duration of disease. The realignment surgery does not produce good results in patients with advanced disease.

Microsatellite instability in solitary and sporadic gastric cancer

Recently, the presence of microsatellite instability (MSI) has been reported in gastric cancer and associated with older age of presentation, distal tumor location, early disease staging, and better overall prognosis. Different characteristics in presentation and in tumor behavior may be explained by different genetic alterations during carcinogenesis of gastric cancer. Identification of specific genetic pathways in gastric cancer may have direct impact on prognosis and selection of treatment strategies. PATIENTS AND METHODS: All 24 patients were treated by radical surgery. Fragments of normal and tumor tissues were extracted from the specimen and stored at -80ºC before DNA purification and extraction. PCR amplification utilizing microsatellite markers was performed. Tumors presenting PCR products of abnormal sizes were considered positive for microsatellite instability (MSI+). RESULTS: Five patients (21%) had tumors that were MSI+ in at least 1 marker. In the group of patients with Lauren's intestinal-type gastric carcinoma, 3 had tumors that were MSI+ (23%), while in the group of diffuse-type gastric cancer, 2 patients had tumors that were MSI+ (19%). The mean age of presentation and the male:female ratio was similar in both groups. Tumors that were MSI+ were more frequently located in proximal portion of the stomach compared to microsatellite-stable (MSS) tumors (40% vs. 16%). Although there was a trend of patients with MSI+ tumors towards a proximal gastric tumor location, early staging, and negative lymph node metastasis, there was no statistical significance compared to those with MSS tumors (P >.1). Comparison of overall and disease-free survival between gastric tumors that were MSI+ and those that were MSS found no statistically significant differences (P >.1). CONCLUSIONS: Microsatellite instability is a frequent event in gastric carcinogenesis and shows a trend towards distinct clinical and pathological characteristics of gastric cancer.

Microphysical evidence of the transition between predominant convective/stratiform rainfall associated with the intraseasonal oscillation in the Southwest Amazon

The distinction between convective and stratiform precipitation profiles around various precipitating systems existent in tropical regions is very important to the global atmospheric circulation, which is extremely sensitive to vertical latent heat distribution. In South America, the convective activity responds to the Intraseasonal Oscillation (IOS). This paper analyzes a disdrometer and a radar profiler data, installed in the Ji-Paraná airport, RO, Brazil, for the field experiment WETAMC/LBA & TRMM/LBA, during January and February of 1999. The microphysical analysis of wind regimes associated with IOS showed a large difference in type, size and microphysical processes of hydrometeor growth in each wind regime: easterly regimes had more turbulence and consequently convective precipitation formation, and westerly regimes had a more stratiform precipitation formation.

Modeling and simulation of forced-air cooling of strawberries using variable convective coefficient

In the forced-air cooling process of fruits occurs, besides the convective heat transfer, the mass transfer by evaporation. The energy need in the evaporation is taken from fruit that has its temperature lowered. In this study it has been proposed the use of empirical correlations for calculating the convective heat transfer coefficient as a function of surface temperature of the strawberry during the cooling process. The aim of this variation of the convective coefficient is to compensate the effect of evaporation in the heat transfer process. Linear and exponential correlations are tested, both with two adjustable parameters. The simulations are performed using experimental conditions reported in the literature for the cooling of strawberries. The results confirm the suitability of the proposed methodology.

Effective diffusivity and convective mass transfer coefficient during the drying of bananas

In this article, a methodology is used for the simultaneous determination of the effective diffusivity and the convective mass transfer coefficient in porous solids, which can be considered as an infinite cylinder during drying. Two models are used for optimization and drying simulation: model 1 (constant volume and diffusivity, with equilibrium boundary condition), and model 2 (constant volume and diffusivity with convective boundary condition). Optimization algorithms based on the inverse method were coupled to the analytical solutions, and these solutions can be adjusted to experimental data of the drying kinetics. An application of optimization methodology was made to describe the drying kinetics of whole bananas, using experimental data available in the literature. The statistical indicators enable to affirm that the solution of diffusion equation with convective boundary condition generates results superior than those with the equilibrium boundary condition.

Instability of a square sheet under symmetric biaxial loading

An early experiment found that a square rubber sheet under symmetric biaxial loading may not remain square. This curious result has been one of the most instructive examples in finite elasticity. Here thermodynamic considerations are used to analyze this instability.

Human DNA repair diseases: From genome instability to cancer

Several human genetic syndromes have long been recognized to be defective in DNA repair mechanisms. This was first discovered by Cleaver (1968), who showed that cells from patients with xeroderma pigmentosum (XP) were defective for the ability to remove ultraviolet (UV)-induced lesions from their genome. Since then, new discoveries have promoted DNA repair studies to one of the most exciting areas of molecular biology. The present work intends to give a brief summary of the main known human genetic diseases related to DNA repair and how they may be linked to acquired diseases such as cancer

Microsatellite instability and cytogenetic survey in myeloid leukemias

Microsatellites are short tandem repeat sequences dispersed throughout the genome. Their instability at multiple genetic loci may result from mismatch repair errors and it occurs in hereditary nonpolyposis colorectal cancer. This instability is also found in many sporadic cancers. In order to evaluate the importance of this process in myeloid leukemias, we studied five loci in different chromosomes of 43 patients, 22 with chronic myelocytic leukemia (CML) in the chronic phase, 7 with CML in blast crisis, and 14 with acute myeloid leukemia (AML), by comparing leukemic DNA extracted from bone marrow and constitutional DNA obtained from buccal epithelial cells. Only one of the 43 patients (2.1%), with relapsed AML, showed an alteration in the allele length at a single locus. Cytogenetic analysis was performed in order to improve the characterization of leukemic subtypes and to determine if specific chromosome aberrations were associated with the presence of microsatellite instability. Several chromosome aberrations were observed, most of them detected at diagnosis and during follow-up of the patients, according to current literature. These findings suggest that microsatellite instability is an infrequent genetic event in myeloid leukemias, adding support to the current view that the mechanisms of genomic instability in solid tumors differ from those observed in leukemias, where specific chromosome aberrations seem to play a major role.

ß-Spectrin São PauloII, a novel frameshift mutation of the ß-spectrin gene associated with hereditary spherocytosis and instability of the mutant mRNA

Hereditary spherocytosis (HS) is a common inherited anemia characterized by the presence of spherocytic red cells. Defects in several membrane protein genes have been involved in the pathogenesis of HS. ß-Spectrin-related HS seems to be common. We report here a new mutation in the ß-spectrin gene coding region in a patient with hereditary spherocytosis. The patient presented acanthocytosis and spectrin deficiency and, at the DNA level, a novel frameshift mutation leading to HS, i.e., a C deletion at codon 1392 (ß-spectrin São PauloII), exon 20. The mRNA encoding ß-spectrin São PauloII was very unstable and the mutant protein was not detected in the membrane or in other cellular compartments. It is interesting to note that frameshift mutations of the ß-spectrin gene at the 3' end allow the insertion of the mutant protein in the red cell membrane, leading to a defect in the auto-association of the spectrin dimers and consequent elliptocytosis. On the other hand, ß-spectrin São PauloII protein was absent in the red cell membrane, leading to spectrin deficiency, HS and the presence of acanthocytes.

Delta sleep instability in children with chronic arthritis

The objective of the present study was to evaluate the expression of a cyclic alternating pattern (CAP) in slow wave sleep (SWS) in children with the well-defined chronic syndrome juvenile idiopathic arthritis (JIA). Twelve patients (9-17 years of age), 7 girls, with JIA were compared to matched controls by age, pubertal stage and gender. After one night of habituation in the sleep laboratory, sleep measurements were obtained by standard polysomnography with conventional sleep scoring and additional CAP analyses. The sleep parameters of the JIA and control groups were similar for sleep efficiency (91.1 ± 6.7 vs 95.8 ± 4.0), sleep stage in minutes: stage 1 (16.8 ± 8.5 vs 17.8 ± 4.0), stage 2 (251.9 ± 41 vs 262.8 ± 38.1), stage 3 (17.0 ± 6.0 vs 15.1 ± 5.7), stage 4 (61.0 ± 21.7 vs 77.1 ± 20.4), and rapid eye movement sleep (82.0 ± 27.6 vs 99.0 ± 23.9), respectively. JIA patients presented nocturnal disrupted sleep, with an increase in short awakenings, but CAP analyses showed that sleep disruption was present even during SWS, showing an increase in the overall CAP rate (P < 0.01). Overall CAP rate during non-rapid eye movement sleep was significantly higher in pediatric patients who were in chronic pain. This is the first study of CAP in pediatric patients with chronic arthritis showing that CAP analyses can be a powerful tool for the investigation of disturbance of SWS in children, based on sleep EEG visual analysis.

Role of chemokines in promoting instability of coronary atherosclerotic plaques and the underlying molecular mechanism

Our aim was to investigate the role of chemokines in promoting instability of coronary atherosclerotic plaques and the underlying molecular mechanism. Coronary angiography and intravascular ultrasound (IVUS) were performed in 60 stable angina pectoris (SAP) patients and 60 unstable angina pectoris (UAP) patients. The chemotactic activity of monocytes in the 2 groups of patients was examined in Transwell chambers. High-sensitivity C-reactive protein (hs-CRP), monocyte chemoattractant protein-1 (MCP-1), regulated on activation in normal T-cell expressed and secreted (RANTES), and fractalkine in serum were examined with ELISA kits, and expression of MCP-1, RANTES, and fractalkine mRNA was examined with real-time PCR. In the SAP group, 92 plaques were detected with IVUS. In the UAP group, 96 plaques were detected with IVUS. The plaques in the UAP group were mainly lipid 51.04% (49/96) and the plaques in the SAP group were mainly fibrous 52.17% (48/92). Compared with the SAP group, the plaque burden and vascular remodeling index in the UAP group were significantly greater than in the SAP group (P<0.01). Chemotactic activity and the number of mobile monocytes in the UAP group were significantly greater than in the SAP group (P<0.01). Concentrations of hs-CRP, MCP-1, RANTES, and fractalkine in the serum of the UAP group were significantly higher than in the serum of the SAP group (P<0.05 or P<0.01), and expression of MCP-1, RANTES, and fractalkine mRNA was significantly higher than in the SAP group (P<0.05). MCP-1, RANTES, and fractalkine probably promote instability of coronary atherosclerotic plaque.

An artificial neural network model for prediction of quality characteristics of apples during convective dehydration

In this study, the effects of hot-air drying conditions on color, water holding capacity, and total phenolic content of dried apple were investigated using artificial neural network as an intelligent modeling system. After that, a genetic algorithm was used to optimize the drying conditions. Apples were dried at different temperatures (40, 60, and 80 °C) and at three air flow-rates (0.5, 1, and 1.5 m/s). Applying the leave-one-out cross validation methodology, simulated and experimental data were in good agreement presenting an error < 2.4 %. Quality index optimal values were found at 62.9 °C and 1.0 m/s using genetic algorithm.

Convective, vacuum and microwave drying kinetics of mallow leaves and comparison of color and ascorbic acid values of three drying methods

Mallow leaves (Malva sylvestris L.) with initial moisture of 5.02±0.003 on dry basis (82.5% on wet basis) were dried using three different drying methods, microwave, convective and vacuum. The leaves that weigh 75 g each were dried until their moisture fell down to 0.10±0.005 on dry basis (approximately 9% on wet basis). The following drying levels were used in each of the drying processes: 6.67, 8.67, 10, 11.33 W g-1 microwave power density; 50, 75, 100 and 125 °C for convective drying; and 3, 7 kPa at 50 and 75 °C for vacuum drying. Drying periods ranged from 6-10, 26-150 and 38-130 min. for microwave, convective and vacuum drying, respectively. Effective moisture diffisuvities ranged from 2.04403 10-10-3.63996 10-12 m2 s-1, 1.70182 10-11-1.10084 10-10 m2 s-1 and 1.85599 10-11-5.94559 10-10 m2 s-1 for microwave, convective and vacuum drying, respectively. According to ascorbic acid content and color parameters, the best microwave power density was found 10 W g-1 with a drying period of 6.5 min.

Energy efficiency and moisture diffusivity of apple slices during convective drying

Abstract The present study aimed at investigating the influences of drying air temperature and flow rate on energy parameters and dehydration behaviour of apple slices. For this purpose, apple slices were dried in a convective dryer at air temperatures of 50, 60 and 70 °C, and air velocities of 1, 1.5 and 2 m s–1. Dehydration rate increased as the air temperature and flow rate increased from 50 to 70 °C and 1 to 2 m s–1, respectively. The effective moisture diffusivity was determined to be in the range of 6.75×10–10-1.28×10–9 m2 s–1. Results of data analysis showed that the maximum energy consumption (23.94 kW h) belonged to 50 °C and 2 m s–1 and the minimum (13.89 kW h) belonged to 70 °C and 1 m s–1 treatment. Energy efficiency values were in the range of 2.87-9.11%. Moreover, the results indicated that any increment in the air temperature increases thermal and drying efficiencies while any increment in the air flow rate decreases both of them.